Field of the Invention
The present invention relates to a structure for protecting structural members located near a heat generation part of an aircraft from heat.
Description of the Related Art
Aircraft are equipped with an air conditioning system which serves to cool and heat, ventilate, and pressurize the cabin etc. This air conditioning system is composed of a compressor, a heat exchanger, a turbine, etc. (e.g., Japanese Patent Laid-Open No. 2004-268617).
Of the components of the air conditioning system of an aircraft, a component which controls temperature and pressure using bleed air taken out from an engine or an auxiliary power unit and air taken in from the outside is installed on the outside of the fuselage. This component (air conditioning pack) is described in Japanese Patent Laid-Open No. 5-163963, for example.
The air conditioning pack includes a control valve which controls the flow rate of bleed air, a turbocompressor which compresses bleed air, etc., and generates heat as it operates.
If the air conditioning pack is installed close to a lower part of the fuselage, heat generated from the air conditioning pack propagates to the lower part of the fuselage facing the air conditioning pack, causing a local temperature rise in the lower part of the fuselage. However, this heat is not released from the lower part of the fuselage to the inside of the fuselage, since a heat insulation material is provided on the inside of the fuselage.
The heat insulation material is provided over the entire inside of an outer shell (the fuselage and the pressure partition wall) which forms a pressurized compartment (e.g., National Publication of International Patent Application No. 2007-517713).
Accordingly, the heat generated from the air conditioning pack is released to the lower part of the fuselage and the surface of the fairing through radiation and convection toward the space between the lower part of the fuselage and the belly faring. For this reason, it makes sense to increase the heat release area by forming the fairing in a larger size so as to be separated from the lower part of the fuselage, and to dispose the air conditioning pack at a lower position so as to be farther away from the fuselage. However, the increased size of the fairing adds to the weight of the airframe. Consequently, the fuel efficiency deteriorates.
Therefore, under constraints on the space and the weight of an aircraft, the present invention aims to protect the structural members from the heat generation part.